Field of the Disclosure
The present disclosure relates to a touch panel, and more particularly, to a liquid crystal display device with an embedded touch panel, in which touch electrodes are formed on a substrate each with divided electrode pieces, and each of which has a touch sensing function by sensing a touch without a button for selecting a particular function, and a method for manufacturing the same.
Discussion of the Related Art
Recently, as the society enters into a fully information oriented society, an industry area relating to display devices for visually expressing electric information signals have rapidly developed. As a result, different flat display devices which are favorable for making the display devices thinner, lighter and to consuming less power have been developed, rapidly replacing existing cathode ray tubes.
As examples of the flat display devices, there are liquid crystal display (“LCD”) device, plasma display panel (“PDP”) device, field emission display (“FED”) device, and electro luminescence display (“ELD”) device, all of which essentially require flat display panels for producing pictures. The flat display panel is provided with one pair of transparent substrates bonded to face each other, with a unique light emission material or polarizing material layer disposed therebetween.
Of the flat display devices, the liquid crystal display device controls light transmissivity of liquid crystals by using an electric field for displaying a picture. To do this, the liquid crystal display device is provided with a display panel having liquid crystal cells, a backlight unit for directing light to the display panel, and a driving circuit for driving the liquid crystal cells.
The display panel includes a plurality of gate lines and a plurality of data lines formed to cross each other to define a plurality of unit pixel regions. Each of the pixel regions has a thin film transistor array substrate and a color filter array substrate facing each other, spacers positioned between the two substrates for maintaining a fixed cell gap, and liquid crystals filled in the cell gap.
The thin film transistor array substrate includes the gate lines and the data lines, a thin film transistor formed as a switching device at every crossed portion of the gate lines and the data lines, a pixel electrode and so on formed at every liquid crystal cell connected to the thin film transistor, and an alignment film coated on the above elements. The gate lines and the data lines have signals supplied thereto through relevant pads.
The thin film transistor supplies a pixel voltage signal from the data line to the pixel electrode in response to a scan signal from the gate line.
The color filter array substrate has a color filter formed at every liquid crystal cell, a black matrix for dividing the color filters and reflecting an external light, a common electrode and so on for supplying a reference voltage to the liquid crystal cells in common, and an alignment film coated on above elements.
Fabrication of the display panel is finished as the thin film transistor array substrate and the color filter array substrate formed individually are aligned and bonded to face each other, and the liquid crystals are injected therebetween.
Recently, demands have been on the rise for the addition of a touch panel to the liquid crystal display device, for perceiving a touched portion made by a hand or additional input means, and provide information in response. Currently, the touch panel is applied to the liquid crystal display device in a fashion in which the touch panel is attached to an outside surface of liquid crystal display device.
In the touch panel may be categorized as a resistive type, a micro capacitive type, an infrared type, and so on according to the type of touch sensing mechanisms used. Taking convenience of fabrication and sensing capability into account, recently the micro capacitance type is gaining attention in smaller sized models.
A related art liquid crystal display device will be described with reference to the attached drawings.
FIG. 1 illustrates a section of a related art liquid crystal display device.
Referring to FIG. 1, the related art liquid crystal display device 1 is provided with a first substrate 10 and a second substrates 20 faced to each other, a thin film transistor array formed on the first substrate 10, a black matrix layer 21 and a color filter layer 22 formed on the second substrate 20, and a liquid crystal layer 15 filled between the first and second substrates 10 and 20.
The color filter layer 22 includes a red color filter layer 22a, a green color filter layer 22b, and a blue color filter layer 22c. 
The first and second substrates 10 and 20 have a first polarizing plate 31 and a second polarizing plate 32 formed on backsides (outer surfaces) thereof, respectively.
If the liquid crystal display device has an IPS mode (In Plane Switching mode) configuration in which the liquid crystal display device is driven by a lateral electric field, a transparent conductive film 35 is formed on the outer surface of the second substrate 20 for shielding static electricity.
In this case, the transparent conductive film 35 is directly sputtered onto the outer surface of the second substrate 20, on which the second polarizing plate 32 is formed.
In this instance, the transparent conductive film 35 is grounded.
However, the related art liquid crystal display device has the following problems.
If the related art liquid crystal display device is produced as a large sized model of a TV set, buttons are separately provided on an outside case at a periphery of the panel for selection of volume or channel, or so on. However, the existence of the outside case which occupies a certain area of a periphery of the panel for providing such buttons impedes production of a narrow bezel or a borderless structure. That is, the area of the outside case, which is not used for actual display, increases.
In order to improve upon the above, an effort is suggested in which the buttons are not separately mounted to an outside case, but provided functionally in the panel.
Accordingly, there has been an effort for providing particular function keys in the panel as particular keys for user's selection while omitting the buttons.